It’s probably one of the last things excavators were planning on unearthing at Ground Zero: an 18th century ship.

On Tuesday, as workers were preparing the site of the September 11 attacks for the future World Trade Center, they uncovered what turned out to be a ship approximately 30 feet below street level. Thought to be from the 18th century, the vessel was uncovered in an area that wasn’t excavated when the original World Trade Center was being built.

Also found nearby was a 100-pound anchor. It’s thought that the ship and the anchor, along with other fragments, were used at one time to fill in land in order to expand Manhattan further into the Hudson River.

As workers continued to prepare the area for building, archeologists worked quickly to record data on the ship, as the sudden exposure to air put the long-buried ship at risk of deteriorating.

Luckily, the rain in New York on Tuesday aided the project. The chief regional archeologist for the New York State Historic Preservation Office, Doug Mackey, told the New York Times that “if the sun had been out, the wood would have already started to fall apart.”